Land of opportunity for Southern Europeans? Germany.

In practice, though, it's more complex. These days, few Europeans grow up with a solid grasp of German, which is still necessary to handle many of the job responsibilities here. The work is also scattered across this Montana-sized country, often far from major cities, forcing the likes of Martinez to make a choice: Live in Berlin – where the rent is cheap, the immigrant network is tight, the entertainment options are endless, but the unemployment rate of 12.3 percent is Germany’s highest – or look for work in another area of Germany where adjustment may be much more difficult but the jobs are more plentiful.

Catalan in Deutschland

On a cobbled crossing in Berlin's trendy Neukölln neighborhood, the Spanish pub Gastón offers a window into this tension.

Skateboarding into work on a Saturday afternoon, owner Bruno Fraysse greets his handful of staff and customers in a mix of Spanish, English, and German. His girlfriend, a Hamburg native, slumps at the bar, lazily swiping her iPad. In the cramped kitchen, young cook Gabriel Sergent, a trained photographer who left Andalusia this summer, is frying fish. A sign on the wall informs: "Every Sunday, Paella!!!"

“When I arrived, it was impossible to hear Spanish on the streets,” says Mr. Fraysse, a firecracker of a figure, whose arms, legs, and chest are covered in tattoos. He moved here from Salou, just outside of Barcelona, in 2006. “Now I can hear Catalan!”